From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Unsuitability of Mercury sparking plugs due to their mica-type construction.
| Identifier | ExFiles\Box 50\2\ Scan020 | |
| Date | 16th November 1920 | |
| To Wd.{Mr Wood/Mr Whitehead} from Hs.{Lord Ernest Hives - Chair} S.Fc X4295 Hs{Lord Ernest Hives - Chair}4/LG16.11.20. X.4295 Re - MERCURY sparking Plugs. The Mercury sparking plugs are of the mica type with the centre portion detachable. At the present time we are not interested in mica plugs. If we make a change at all it will certainly be to a sparking plug which has a pot or porcelain type of insulator. If it is desired, we could return the Mercury plugs to the Makers as we have only used one of them. Hs.{Lord Ernest Hives - Chair} [STAMP: RECEIVED NOV 17 1920] R R.{Sir Henry Royce} 285A (100 T. S.H. 89. 22-7-20) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 2789 | ||